The present invention relates to a method for the removal, addition, or exchange of marbling fat within meat pieces, an apparatus for practicing the method, and the meat product produced by practicing the method using the apparatus. The present invention can remove fat from meat, add fat to meat, or exchange marbling fat for another type of fat, or another material entirely.
1. Field of the Invention
A fundamental dichotomy exists in American dietary consumption of meat products between "healthy eating" and "good eating." On one hand, the epidemiological data linking increased blood cholesterol levels and high dietary intake of saturated fats with increased risk of heart disease has led Americans to decrease their consumption of red meats, and meat products in general. This is due mostly to the fact that hard marbling fat, present in finer cuts of beef in particular, is very high in cholesterol and saturated fats. As a result, per capita consumption of red meat in the United States has dropped steadily since 1976. On the other hand, the general public continues to associate well marbled cuts of meat with good eating quality. The present invention is aimed at solving this dilemma in which both meat vendors and meat consumers find themselves. In effect, the present invention provides both "healthy eating," and "good eating," simultaneously.
It is now widely recognized that blood cholesterol levels can be a major indicator in determining whether or not an individual will suffer from heart disease. Individuals with higher blood cholesterol levels generally have a greater risk of developing heart disease than individuals with lower levels of cholesterol. It is also believed that an individual's blood cholesterol level is influenced by a number of diverse factors, some genetic in origin, others environmental in origin. It is known, however, with certainty, that one environmental factor which affects blood cholesterol level is diet.
The major environmental factor which contributes to a relatively high blood cholesterol level is a diet high in saturated fats. A saturated fat (also called a "hard" fat) is a fat which generally has no double or triple bonds (i.e. has no points of unsaturation). It is known that animal fats are generally high in saturated fat content. These hard, saturated fats include such fatty acids as lauric acid, myristic acid, palmitic acid and stearic acid. "Soft," or unsaturated fats have not been implicated in heart disease. Some, such as linoleic acid, linolenic acid, and eicosapentaenoic acid are either essential nutrients, or are metabolic antagonists to the harmful saturated fats and sterols, including cholesterol. Other unsaturated fats, such as arachidonic and eicosatrienoic acids, are precursors of prostaglandins, which are important triggers of various human biological responses. With the exception of a trace of arachidonic acid, all of the beneficial unsaturated fatty acids listed above are almost entirely absent from the fat found within red meat. Therefore, a simple way to lower blood cholesterol levels is to limit the intake of red meat, and hence the intake of harmful fatty acids and cholesterol.
The "hard" and "soft" designation for saturated and unsaturated fats, respectively is in reference to the melting points of the different types of fat. Fats melt at sharply lower temperatures as the amount of unsaturation within the fat molecule increases. As a thumbnail rule, then, the lower the melting point of a fat, the greater its unsaturation, and therefore the lesser its health risks.
Unfortunately, many individuals are unwilling to modify their diets to reduce their intake of saturated fats. In order to significantly lower blood cholesterol levels, it is necessary to reduce the dietary intake of animal products, and red meat in particular, and to replace it with vegetable products or other meat products such as fish and poultry, which are lower in saturated fats.
Therefore, what is needed, and what the present invention addresses, is the need for control of fat composition and quantity, not merely the total elimination of fats. As noted above, a certain amount of fat within meat is necessary to give the meat good organoleptic qualities. The present invention allows the substitution of harmful saturated fats with beneficial (or at least less harmful) polyunsaturated fats. The present invention also allows for the introduction of marbling soft fat into lean pieces of meat. Also, if desired, the present invention can remove fat from a cut of meat, without putting anything in its stead. Equally important, the present invention can do all of the above without comminuting the meat, and without changing the appearance or flavor of the meat.
In regard to the animals to be consumed themselves, altering the type and distribution of fat within food animals via breeding and management is a problem which continues to plague feed-lot managers and animal breeders. While genetics does play some role in the fat content of food animals, in ruminants such as cattle, sheep and goats, it is the metabolism of the rumen organisms which ultimately controls metabolic intake. Because the rumen organisms are controlled by their own genes, their metabolic activity is genetically independent from that of the animal,
It is true however, that the gross quantity of meat fat within an animal can be controlled by animal management, such as grass feeding. However, feed-lot or open range grass feeding is a low productivity practice, and the meat produced by such programs has not won high praise in the American beef market. For the present, and the foreseeable future, the grain-fed animal is the only source of tender, juicy, high value red meats. Unfortunately, such grain-fed animals are also the main source of meat marbled with hard, saturated fat.
In addition to saturated and unsaturated fats, animal fat can also be characterized by where it is found within the animal. In general, fat is found in one of two types of deposits: depot fat or marbling fat. Depot fat accumulates in thick layers outside the muscles. Marbling fat comprises thin streaks within the muscles themselves. Depot fat can be trimmed from the meat by hand, whereas marbling fat cannot.
Within the muscles, marbling fat is held as a single droplet inside a large specialized cell. These fat cells aggregate as thin streaks along small blood vessels within the muscle. Individual cells may be as large as 0.1 mm. The average size of the fat cells increases with the total fat content of the meat, and the size of the local fat accumulation.
These marbling fat cells are rather delicate, but in the raw state remain intact and separated from one another by thin cell walls formed almost entirely of proteins. However, the fat cells rupture when the meat is cooked. This empties the contents of the cell into the surrounding meat. Because most of the compounds which give meat its characteristic flavor are fat-soluble, it is the contents of the marbling fat cells that imparts to the meat its characteristic aroma and flavor.
2. Description of the Prior Art
Numerous methods and machines have been devised to remove fat from animal carcasses immediately following slaughter, to tenderize tough cuts of meat, and to lower the fat and cholesterol content of finished cuts of raw meat. For instance, U.S. Pat. No. 1,334,694, issued Mar. 23, 1920, to Dufresne et al, describes an apparatus to cut external fat from slaughtered animal parts. The animal parts are drawn through heated rolls, and forced over large cutting blades which remove external fat from the pieces. The fat so removed is then recovered for further processing. U.S. Pat. No. 3,091,791, issued Jun. 4, 1953 to Czaper, Jr. discloses a meat scraper for removing bone dust and fat residue from frozen meat which has been cut with a power saw. The meat scraper includes a resilient blade which will remove the offensive bone particles and other contamination from the meat, without marring the surface of the meat.
U.S. Pat. No. 3,916,777, issued Nov. 4, 1975, to Earl, describes a meat tenderizing system in which a pistol-like device having a plurality of needles is used to inject an enzyme solution into whole, dead, meat-bearing carcasses. The enzyme solution, which prevents toughening of the meat, is injected into the animal carcass immediately after the animal is killed, while the temperature of the carcass is still within body temperature range. The apparatus used to inject the solution consists of a plurality of multiple-needle injectors, and associated holding tank and pumping means, which are used to pump the enzyme solution into the slaughtered carcasses. The needles do not reciprocate, nor does the apparatus remove fat or any other substance from the carcasses.
Chapman, U.S. Pat. No. 4,778,682 (issued Oct. 18, 1988) describes a method of preparing a low-fat, low cholesterol raw meat product. The method has two steps: The first step is to expose a thin layer of meat to ultraviolet light. The second step is to comminute the meat in a chilled bowl with the addition of cold water, acid, and salt and food phosphates. A quantity of fat and cholesterol will separate from the meat emulsion and adhere to the surface of the chilled bowl. The drawback to this process is that it cannot be performed on whole roasts or cuts of meat, but can only be used to treat comminuted meats such as ground beef.
Another method to lower the fat content of ground meats is disclosed in U.S. Pat. No. 5,082,678, issued Jan. 21, 1992 to Margolis. The Margolis method consists essentially of heating a patty of ground meat to a given temperature (45.degree. C. for ground beef patties), and applying pressure to the cooked patty to exude a quantity of fat from the patty. This reference contains no mention performing the method on a whole piece of meat, such as a roast. The Margolis patent also describes injecting a flavoring solution into meat patties after they are cooked, so as to replace the non-fat moisture and flavors which are exuded from the meat patty along with the fat.
Paulus, U.S. Pat. No. 5,250,006, issued Oct. 5, 1993, describes an apparatus for tenderizing whole cuts of meat. The apparatus includes a stage on which the meat is placed, and an array of tenderizing knives which can be embedded and removed from the meat. The spaced tenderizing knives can be easily removed from the apparatus to facilitate cleaning and to lessen the chance of accidental injury to the operator from the sharp blades. The blades are not hollow, nor are they temperature controlled in any manner.
A Canadian Patent, No. 685,130, issued Apr. 28, 1964 to Wittag, discloses an apparatus to treat the surface of meats to facilitate the adhesion of small pieces of meat to form larger pieces of meat. The apparatus strikes the meat surface with a plurality of whip-like cords. This ruptures the surface cells of the cut of meat, which releases liquids which increase adhesion of the meat pieces.
Japanese Patent J6-1158-763-A describes the removal of surface fat derived from blocks of beef or pork using sheets of material made of a hydrophobic and lipophilic material such as polypropylene. Japanese Patent JO-3164-130-A describes a meat tenderizer which has controlling means to ensure that the tenderizing blades of the tenderizer only pierce the hardest portions of the cut of meat.
A 1962 article and accompanying advertisement from The National Provisioner (Mar. 3, 1962) describes an apparatus for injecting hot fat or other liquids into whole cuts of meat to create artificial marbling. The apparatus includes a pumping unit and a four-prong injector for pumping liquids into meat. The article only describes injecting fat or other liquid into lean, well-muscled meat. There is no discussion regarding removing fat from cuts of whole meat.
None of the above references, taken alone or in any combination, is seen as teaching or suggesting the present invention.